IMMUNOGENETICS — PAST, PRESENT, FUTURE

The study of the gene pool of domestic breeds and the issues of preservation of national breeding resources are currently of great importance. In this connection, the possibilities of assessing the genetic situation in the selection of the Kholmogorsk breed, one of the oldest domestic breeds of cattle with dairy productivity, are particularly relevant. At present the most accessible monitoring form is the actualised characteristic of types and herds on allelophal of blood group systems. So comparison with initial traits in already existing herds, formalises novelty, selection value of breed inbred and factory types. The article presents the methodology of establishing the genetic passport of breed affiliation in the form of a scheme, its approbation in the breeding reproducer OS 'Kotlasskaya' - branch of FGBNU 'FIC potato named after A.G. Lorkh'. The importance in determining the status of breeding animals of the Holmogorsk breed of cattle for the purposes of registration in the federal state information-analytical system of breeding resources of the Russian Federation was noted. The results of immunogenetic testing for the reliability of origin of cattle in the controlled breeding reproducer for the last 5 years showed that the total number of tested for reliability of origin was 740 heads. It was found that the percentage of reliability in genotyped herd stock ranged from 96.5% (2022) to 99.3% (2020). For approbation of the methodology of establishing the genetic passport of breeding animals of the breed with bloodlines up to 75% Holstein, allowed for breeding purposes when working with Kholmogorsk cattle, we carried out the corresponding immunogenetic testing. Immunogenetic testing of breeding animals of the farm revealed 38 alleles of EAB locus, including 19 alleles with frequency higher than 1%. At the same time, the total frequency of EAB locus alleles in animals of groups 1–2 (with specific (or typical) for the Kholmogorsk cattle breed and with unique alleles) was 76.67%. Accordingly, in group 3 of controlled animals (with alleles of the approved Holstein breed of cattle), the total frequency was found to be 23.24%. Whereas in group 4, which included animals with alleles of non-admitted breeds — 0.09%. It was also found that the concentration of alleles in animals of the Holmogorsk breed G2O2, B2G2KA'B'G'O'G', B2F'2G', B2I2, B2O2Y2D' is extremely low, they are found only in some individuals. We found the degree of homozygosity (theoretical) at 6.9%, and the number of effective alleles, respectively, at 14.5. The coefficient of genetic similarity between fixed bulls-producers and breeding stock in the farm was 0.654.

Kholmogorsk breed, genetic passport, alleles of the EAB blood group locus, total allele frequency, breeding reproducer OS "Kotlasskaya" — a branch of the Federal State Budgetary Scientific Institution 'A.G. Lorkh Potato Research Centre'